Raypak 503-2003 manual Modulating Temperature Control, High and Low Gas Pressure Switches Optional

SECTION C: Installation

Fig. 32: Flow Switch

Modulating Temperature Control

The heater is equipped with a Raypak modulating tem- perature control. Refer to information starting on page 28 for information on the setting and use of this control.

Fig. 33: Modulating Temperature Control

High and Low Gas Pressure Switches (Optional)

The optional low gas pressure switch connection mounts upstream of the gas valve (on the inlet flange to the gas valve) and is accessible through the removable access panels on the rear of the heater to reset the gas pressure switch, as necessary. It is used to ensure that sufficient gas pressure is present for proper valve/regulator performance. The low gas pressure switch automatically shuts down the heater if gas sup- ply drops below the factory setting of 3.0 in. WC for natural gas or LP gas.

The optional high gas pressure switch connection mounts down-stream of the gas valve. Special ports are located on the backside of the gas valve and acces- sible from the front of the heater (to reset the gas pressure switch) or through the removable access pan- els on the rear of the heater (to reset the gas pressure switch), as necessary. If the gas pressure regulator in the valve fails, the high gas pressure switch automati- cally shuts down the burner.

Operation of either the High or Low Gas Pressure Switch will turn on an LED inside the switch housing. Push the top of the plastic switch housing as shown in Fig. 35 to reset a tripped pressure switch. The LED will go out when the switch is reset.

Low Water Cut-Off (Optional)

The optional low water cut-off automatically shuts down the burner whenever water level drops below the level of the sensing probe. A 5-second time delay pre- vents premature lockout due to temporary conditions such as power fluctuations or air pockets.

Fig. 34: Low Water Cut-Off

Fig. 35: High/Low Gas Pressure Switch

Air Pressure Switch

The heater is equipped with an air pressure switch to prove the operation of the blower before allowing the ignition control to begin a Call for Heat. It is located on the right side of the lower flange of the blower mounting assembly, directly behind the junction box.

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